[PATCH] clocksource: dw_apb_timer_of: support timer-based delay

Daniel Lezcano
2015-10-30T10:44:46Z

On 10/30/2015 09:27 AM, Jisheng Zhang wrote:
> Implement an ARM delay timer to be used for udelay(). This allows us to
> skip the delay loop calibration at boot on Marvell BG2, BG2Q, BG2CD
> platforms. And after this patch, udelay() will be unaffected by CPU
> frequency changes.
>
> Signed-off-by: Jisheng Zhang <jszhang@marvell.com>
> ---
> drivers/clocksource/Kconfig | 10 ++++++++++
> drivers/clocksource/dw_apb_timer_of.c | 16 ++++++++++++++++
> 2 files changed, 26 insertions(+)
>
> diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
> index a7726db..7b081805 100644
> --- a/drivers/clocksource/Kconfig
> +++ b/drivers/clocksource/Kconfig
> @@ -29,6 +29,16 @@ config DW_APB_TIMER_OF
> select DW_APB_TIMER
> select CLKSRC_OF
>
> +config DW_APB_TIMER_BASED_DELAY
> + bool "DW APB timer based delay"
> + depends on ARM && DW_APB_TIMER_OF
> + default n
> + help
> + This option enables support for using the DW APB timer to
> + implement timer-based delay. It is useful for skiping the
> + delay loop calibration at boot on some platforms. And the
> + udelay() will be unaffected by CPU frequency changes.
> +

Why do you want it to be optional ?

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